The British embassy said on Twitter that its flags in Dubai and Abu Dhabi had been lowered to half mast as a mark of respect.

'More steadfast'

Abu Dhabi's crown prince and UAE's acting armed forces chief, Mohammed bin Zayed Al Nahyan, said "these events will only make us more steadfast in our stand for justice".

The UAE said the incident would not sap its commitment to the Arab coalition's mission to restore exiled President Abd-Rabbu Mansour Hadi.

The White House said US President Barack Obama telephoned Mohammed bin Zayed on Saturday to offer his condolences.

For their part, the Iran-allied Shia Houthi fighters described the missile attack as "revenge" for six months of deadly Arab coalition air raids.

The Houthis said they had used a Tochka missile to attack the Safer camp in Marib.

Marib has seen fierce fighting as loyalist forces and their coalition allies have advanced in Yemen's north.

The coalition launched an air war when Hadi fled to Saudi Arabia in March and Houthis and their allies entered the exiled president's last refuge, Yemen's second city Aden.

After loyalists recaptured Aden in July, the Arab coalition launched a ground operation that has seen the rebels pushed back from five southern provinces, although they still control Sanaa and much of the north and centre.

More than 4,500 people have been killed in the conflict, including hundreds of children, according to the UN, which has warned that Yemen is on the brink of famine.